/**
 * Convert a single file-input element into a 'multiple' input list
 *
 * Usage:
 *
 *   1. Create a file input element (no name)
 *      eg. <input type="file" id="first_file_element">
 *
 *   2. Create a DIV for the output to be written to
 *      eg. <div id="files_list"></div>
 *
 *   3. Instantiate a MultiSelector object, passing in the DIV and an (optional) maximum number of files
 *      eg. var multi_selector = new MultiSelector( document.getElementById( 'files_list' ), 3 );
 *
 *   4. Add the first element
 *      eg. multi_selector.addElement( document.getElementById( 'first_file_element' ) );
 *
 *   5. That's it.
 *
 *   You might (will) want to play around with the addListRow() method to make the output prettier.
 *
 *   You might also want to change the line 
 *       element.name = 'file_' + this.count;
 *   ...to a naming convention that makes more sense to you.
 * 
 * Licence:
 *   Use this however/wherever you like, just don't blame me if it breaks anything.
 *
 * Credit:
 *   If you're nice, you'll leave this bit:
 *  
 *   Class by Stickman -- http://www.the-stickman.com
 *      with thanks to:
 *      [for Safari fixes]
 *         Luis Torrefranca -- http://www.law.pitt.edu
 *         and
 *         Shawn Parker & John Pennypacker -- http://www.fuzzycoconut.com
 *      [for duplicate name bug]
 *         'neal'
 */
function MultiSelector( list_target, max ){	
	// The delete ico path:
    this.deleteIconPath = '<?= $GLOBALS["CONF"]["url"]["admin"] ?>/images/content/ico_trashcan.gif';
	// Where to write the list
	this.list_target = list_target;
	
	// How many elements?
	this.count = 0;

	this.prefix = "";
	// How many elements?
	this.id = 0;

	// Is there a maximum?
	if( max ){
		this.max = max;
	} else {
		this.max = -1;
	}

	/**
	 * Set's a path for the delete icon:
	 */
    this.setDeleteIcon = function (path) {
        this.deleteIconPath = path;
    }
    
	this.addPrefix = function (prefix)
	{
		this.prefix = prefix;
	}
	/**
	 * Add a new file input element
	 */
	this.addElement = function( element ){

		// Make sure it's a file input element
		if( element.tagName=='INPUT' && element.type=='file' ){
            //element prefix
            element.prefix = this.prefix;

			// Element name -- what number am I?
			element.name = this.prefix+'multiple_file[' + (this.id++) +']' ;
			// Add reference to this object
			element.multi_selector = this;

			// What to do when a file is selected
			element.onchange = function()
			{
				// New file input
				var new_element = new Element('input');
				new_element.type = 'file';

				// Add new element
				this.parentNode.insertBefore( new_element, this );

				// Apply 'update' to element
				this.multi_selector.addElement( new_element );

				// Update list
				this.multi_selector.addListRow( element );

				// Hide this: we can't use display:none because Safari doesn't like it
				this.style.position = 'absolute';
				this.style.left = '-1000px';
			}
			// If we've reached maximum number, disable input element
			if( this.max !=-1 && this.count >= this.max )
			{
				element.disabled = true;
			}
			// File element counter
			this.count++;
			// Most recent element
			this.current_element = element;
			
		} else {
			// This can only be applied to file input elements!
			alert( 'Error: not a file input element' );
		}
        this.id++;
	}

	/**
	 * Add a new row to the list of files
	 */
	this.addListRow = function( element ){
		var buffer = '<tr class="row" id="item_'+ this.count +'"><td>'+ element.value +'</td><td class="LastColumn"><img src="'+this.deleteIconPath+'" onclick="multi_selector.removeItem(\'item_'+ this.count +'\')" class="clickable"/></td><tr>';
		$(this.list_target).insert(buffer);
	}
	
	this.removeItem = function (item)
	{
		$(item).remove();
	}
}
